The Age of Autism: Many, many more

WASHINGTON, Oct. 16 (UPI) -- The debate over the cause or causes of autism has been hung up for years on a point that should have been settled by now: whether the rate is in fact increasing.

This column long ago concluded that, yes, the autism rate has risen dramatically over the past couple of decades. What's more, the disorder seemed to arise out of nowhere starting about 1930.

Both those points are controversial, to say the least. If in fact autism went from essentially zero in 1930 to 1-in-every-166 kids today, the prime suspect would be some new harmful exposure, not merely better recognition of a genetic, highly heritable disorder.

The issue can quickly get complicated: How do you define autism? How have the diagnostic boundaries changed? Is an autism diagnosis being substituted for mental retardation because it sounds less devastating or more, well, fashionable?

But all this is not as hard to untangle as some parties would have you believe. In 1943 a Johns Hopkins child psychiatrist named Leo Kanner identified the syndrome in a landmark paper, "Autistic Disturbances of Affective Contact." The 11 case histories he described among children born starting in 1931 were remarkably similar -- and "markedly and uniquely" different from anything previously reported, Kanner said.

Ultimately, a broader spectrum of pervasive developmental disorders was included -- from the milder Asperger's to Rett's Syndrome, which affects girls, to Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS).

The severe form first described by Kanner came to be known as "full-syndrome," "classic" or simply "Kanner autism."

That easily identifiable disorder is what we want to compare. I've suggested the current incidence of Kanner autism is somewhere between 40 to 60 children per 10,000; when you add in the other disorders on the spectrum, it rises to 60 to 80 per 10,000.

Of course, there is debate and uncertainty -- but within fairly tight parameters. Dr. Deborah Hirtz of the National Institute of Neurological Disorders and Stroke -- part of the National Institutes of Health -- estimates that about 10 to 30 children per 10,000 have classic autism today, and a combined total of 30 to 60 have one of the pervasive developmental disorders.

That's slightly lower than my numbers, but on the same order of magnitude.

Too bad, some say, we can't match those up with reliable figures from before 1980; then we would know if we're facing a real increase. The most frequent objection is the lack of a large, pre-1980 "prospective" study -- one that followed thousands of kids and recorded which ones developed the classic signs of autism. That would be a fair basis for comparison.

I've recently come across a 1975 study that does exactly that, although it was not the purpose of the research. The study was designed to look at bleeding during pregnancy as a risk factor for autism and childhood psychosis -- and did find a correlation. To do so, it examined the computerized records of 30,000 kids -- a huge sample -- born between 1959 and 1965 at 14 university-affiliated medical centers. All the children got several neurological, psychological and speech and hearing exams by age 8.

Here's the key statement: "From this group 14 were selected as conforming to the syndrome of infantile autism."

That translates to 4.7 kids per 10,000, way lower than any measure of today's rate. The researchers wrote that although they "make no claim to having identified every autistic child among the 30,000 children, the rate of 4.7 per 10,000" exactly matched another well-regarded study, "leading us to believe that most such children were included."

But what about kids who back then were mistakenly labeled schizophrenic or had other "pervasive" disorders that now would land them on the autism spectrum? Well, the researchers studied the records again and, this time, identified "additional children who, although not having the classical syndrome of infantile autism, were apparently psychotic. Six such children were found, all labeled by at least one observer as severely disturbed, psychotic-like, autistic, or childhood schizophrenic."

So let's include them in our "autism spectrum." That gives us 14 classically autistic kids, plus six more with some sort of severe developmental disorder, for a total of 20 kids out of 30,000.

Again, the math is simple -- that's just 6.7 kids per 10,000, far below even the low-end estimate of 30 per 10,000 for all the spectrum disorders today cited by the NIH's Hirtz.

The study was published in the highly credible "Journal of Autism and Childhood Schizophrenia" in 1975. And get this: "Children with infantile autism and childhood psychosis were identified by the National Institute of Neurological Disease and Stroke Collaborative Pre-Natal Study." That's Hirtz's institute.

We're talking apples and apples, and a lot more of them today than 35 or 40 years ago. The implications are as disturbing as they are (or should be) obvious.

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